Problem: Simplify the following expression: $q = \dfrac{t}{2} - \dfrac{9t}{2}$
Explanation: Since the expressions have the same denominator we simply combine the numerators: $q = \dfrac{t - (9t)}{2}$ Combine like terms: $q = \dfrac{-8t}{2}$ Simplify by dividing numerator and denominator by 2: $q = \dfrac{-4t}{1}$ $q = -4t$